Nerium oleander is a bushy, evergreen shrub that grows thickly and quickly in almost any conditions - but is poisonous (if eaten in sufficient quantities).
It has long, slim leaves and bright, star-shaped, open,creamy/white flowers.
Its dense bushy fast-growing nature lends itself well to hedging - but ensure you plant rows of the same variety as they have different foliar characteristics.
Other varieties include:
"Algiers" - has bright red flowers.
"Monsieur Belaguier" - has pink flowers.
"Splendens Variegata" - bears double pink flowers and the leaves have a gold variegation. This cultivar tends not to flowers too profusely, but the attractive, year-round foliage makes up for this.